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H. O. DAVIDSON AND O. HILLMAN.

CONCRETE FORM.

APPLICATION FILED MAR. 29, 1917.

1,324,881 Patented Dec. 16, 1919.

3 SHEETS-SHEET l- H. O. DAVIDSON AND O. HILLMAN.

CONCRETE FORM.

APPLICATION FILED MAR. 29. 1917.

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Patented Dec. 16, 1919.

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H. O. DAVIDSON AND 0. HILLMAN.

CONCRETE FORM.

APPLICATION FILED MAR.29,1917.

Patented Dec. 16,1919.

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HAIR-R170. navinson Ann orro martian, or CLEVELAND, OHIO, assrenons ToTHE nvnnann c rnnssnn ceiurarir, onnvnnannonto, A CORPORATION 01%v OHIG.

Specification of LettersPatent. Patented Dec. 16, 1919.

Application filed March 29, 1917. Serial No. 158,282.

To all whom it may concern:

Be it known tnat we, HARRY O. DAVIDSON and O'r'ro HILLMAN, citizens ofthe United States, residing at Cleveland, in the county of Cuyahoga andState of Ohio, have invented a certain new and useful ImprovementinConcrete-Forms, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings.

This invention relates to concrete mold forms, and particularly tointernal forms for use in molding sewers, culverts, conduits and thelike; and the inventionhas for its general objects the production of aform of the foregoing nature which 1s collapsible; which iscomparatively light, and conven ent of handling, and which is made uplongitudinally of sections arranged'to overlap or telescope within oneanother in the production of a continuous mold form of the requiredlength.

Further and more specific ob ects are the production of a concrete moldform of the above character which comprises flexible segmental plateshaving longitudinal engaging edges that are turned inward sufficientlyoblique to a line radial with respect to the plates to afiord easyremoval of tl ieplates; to provide effectual retainers for alinlng andsupporting the form plates, the same being readily collapsible; and theprovision of a device for clamping together and alining the adjacentedge portions of adjoining plates.

Constructions wherein the foregoing objects are attained are illustratedin the drawings accompanying and forming a part hereof, and whereinsimilar reference characters designate corresponding parts throughoutthe several views.

Figure 1 is a transverse section of the mold form, such section beingtaken on the line 11 of Fig. 2; Fig. 2 is a longitudinal section on thecorrespondingly numbered line of Fig. 1; Fig. 3 is a sectional detailthrough the form adjacent the connected ends of a support or retainer;Figs. 4 and 5 are sections on the line 4 .t and 5-5 respectively, ofFig. 3; Fig. 6 is a horizontal section on the line 66 of Fig. 3; Fig. 7is a view, similar to Fig. 3 showing the couplers through which adjacentends of adjoining sections ofthe support orretainer are connected; Fig.8 is a horizontal-section on the line 8-8 of Fig. 7 Fig. 91s aperspect've view of the device for clamping and alining adjacent edgeportions of adjoining plates; igs. 10 and 11 are elevations of thedevice, the views being taken at right angles to each other; and Fig. 12is a transverse section through a mold form'involving three segmentalsections.

The form plates are designated 1 and their their edge portions justdescribed permits them to be readily disengaged from each other afterthe concrete hardens, the edge portion of one of the plates forming anobtuse angle with its adjacent body portion, while the other forms a'complementary acute angle the angular portion being such that the one ofgreater angle may be readily withdrawn fromengagement with the other byflexing the plate. I

It has been stated above that the form is divided longitudinally intosections, and that the ends of adjacentsections overlap or telescope oneinto the end of the other. This arrangement is dependent somewhat uponthe flexibility of the plates for thereason that the end of one platemay be inserted. into the end of another with its edge portions 2fitting into the corresponding portions of the said other plate, andwhen the clampmg devices and retalners are applied to the formthestelescoping joint does not affect its accuracy of size or shape. Itmay be explained that the relative thickness of the form plates and thesize of the various clamping and retaining elements are somewhatexaggerated in the drawings for the obvious purpose of clearness ofillustration. When the actual thickness of plates used in practice iscompared with the size of the forms, which may be a number of feet indiameter, it will be seen that the surface of the form at the joint willbe comparatively smooth. V

The adjacent edge portions of adjoining form plates are clamped togetherby the device illustrated in detail in Figs. 9 to 11, the presentembodiment consisting of opposed jaws 5 and 6, which have bearing heads7 at one end and are pivoted together upon a bolt 8 at the other. Thejaws are adapted to be drawn toward each other by a bolt 10 which passesthrough a transversely elongated opening 11 in the jaw 6, and the boltis arranged to have the portion adjacent its head 12 contained within anotch 13 which opens through the side of a boss 1st of the jaw 5. Theouter face of the boss is flat for engagement with the head of the bolt10 and adjacent the open side of the notch, has lugs 15 which overhangthe side of the head and prevent its turning when the wing nut 16 ismanipulated upon the threaded end of the bolt for the purpose of drawingtogether or permitting the separation of the jaws. The notch affordsready removal of the headed end of the bolt upon a slight unscrewing ofthe wing nut sufficient to allow the head to pass the lu s 15 whereforethe clamp may be very quickly and easily applied to and disengaged fromthe edge portions of the plates. The bearing heads 7 are angularlydisposed to the jaws so that when the clamp is applied to the obliqueedge portions 2, it is substan tially radially disposed with respect totheform.

Journaled upon the bolt 10 between the jaws is a cam 18 which isarranged to have its periphery swung into engagement with the flanges 3of the form plates, and upon having its radially enlarged portion forcedinto contact with said flanges as it is rotated upon the bolt 10 by theblows of a hammer or other means, it forces the flanges, andconsequently the body portions of adjoining plates, into proper relativepositionsthat is, until the outer surfaces of the plates aresubstantially flush. 'In this open ation the bolt 10 acts as anabutment, fixed with respect to the jaws, and opposed to the flanges 3and between which and the flanges the cam 13 is adapted to be wedged.

Thus the clamping device provides a very convenient means of securingthe plates together. and properly alining them, which means is durable;comparatively simple and inexpensive of manufacture, and is readilyoperable under conditions prevailing in the construction of concretemasonry.

Form supports or retainers 20 are distributed along the form at suitabledistances apart for holding the forms distended in proper shape andsize. Each support or retainer comprises a plurality of segmentalsections 21 that are pivotally connected throughout the circumference ofthe retainer by couplers 22, except where the ends of the retainer aretemporarily connected by a conpler 23. It may be briefly explainedbefore describing the retainer in detail that it is made collapsible forthe obvious purpose of facilitating its placement and removal; and sincethe shape of the form is practically determined by the retainer, it isessential that it be accurate in shape when in use. To this end weprovide means for forcing the adjacent ends of adjoining sections of theretainer into alinement and for effectually holding the parts in suchposition. Such means is required where the retainer comprises more thanthree sections, for in cases where the retainer comprises three sectionsor less, there is no tendency for the parts to get out of alinementafter the ends of the retainer are connected, as will be furtherexplained hereinafter. While we have shown a circular form in thedrawings, it is obvious that the alining feature of the retainer wouldbe of equal importance in forms of other shapes.

The coupler 23 through which the ends of the retainer be connected isillustrated in detail in Figs. 3 to 6. The sections 21 are preferably Tshaped in crosssection, and to one side of the central flange of one endof the retainer is connected the upper end of an L-shaped plate 25, theplate being turned inward beneath and into the plane of the flange asshown particularly in Fig. 5. A smaller plate 26 is applied to theopposite side of the flange and extends down over the adjacent portionof the plate 25 where it is connected to said plate by rivets 27. Theplates 25 and 26 are secured to the opposite sides of the flange of thesection 21 by rivets 28. Plates 30, similar in shape to the plate 25 butreversed as to position, are pivotally connected to the central flangeof the opposite end of the retainer by a bolt 31, the plates being heldin operative position by a pin 32 which passes through aliniug holes inthe' plates and flange. The plates being spaced apart a distancesubstantially equal to the thicknessof the flange permits the endportion of the plate 25 to enter between the corresponding portions ofthe plates 30, and these portions of the various plates have registeringopenings for the reception of a wedge 33 whereby the ends of theretainer may be forced apart to expand the form to the accurateaggregate size of the plates 1. The fact that the plates 30 are pivotedto the retainer allows them after the pin 32 has been removed to be swundown out of the way of the opposite end of the retainer when the same iscollapsed.

The pivotal coupler 22 is illustrated in detail in Figs. 7 and 8and'comprises an entering plate 35 which is connected, with the smallerplate 36 to th central flange of the retainer by rivets 3T.Correspondingly shaped plates 38 are connected, by the rivets 39, to theadjacent end of the adjoining section and these plates are adapted toreceive between their end portions the end portion of the plates 35, theoverlapping portions of the plates 35 and 38being pivotally connected bya bolt 40. The plates 38are spaced apart below the flange of the section21by a filler 41 that is held in place by the rivets 42. It willbeobserved that the outer ends of the plates 38 are extended'to overlieconsiderable of the body portion of the plate 35, and the adjacentportions of these plates are provided with registering openings for thereception of a key 43 which is shown as wedge-shaped. It is by means ofthese keys that the parts may be forced into proper relation to eachother with the'adjacent ends of the sections 21in alinement, for it willbe seen that if the key receiving openingsare slightly out of alinementbefore the key is inserted, the driving of the key into the openingswill force the opening into absolute register, and with the other partsbearing the proper relation to the openings, they are bound to assumecorrect relation.

One of the adjacent ends of the adjoining sections is cut away on anincline, as shown at 15, to permit it to pass the adjacent inturned edgeportions of the form plates; and it will be noted that the couplers areamply recessed for the accommodation of such portions. 1

In Fig. 12, we have shown a form in which the circumference is made upof but three segmental plates 1 and the retainer 20 comprises acorresponding number of sec-- tions which arepivoted together bycouplers 22 which are identical in every respect with the formercouplers 22 except for the omission of the keys, for it will be recalledthat in forms of three circumferential sections or less, alinementdevices for the retainer sections are unnecessary since, when the endsof the retainer are joined, it can assume nothing but a true circle (orother normal shape, whatever that may be).

We claim- 1. A form made up circumferentially of a plurality ofinterchangeable transversely curved flexible plates, the adjacent edgesof adjoining plates being turned inward for engagement with each otherat an angle oblique to theradius of the plates.

2. A retainer for forms of the character set forth, said retainercomprising sections, and means pivotally connecting adjacent ends ofadjoining sections and including means bywhich said ends may be forcedinto and retained in proper relation to each other.

3. A retainer for forms of the character set forth, said retainer beingarranged to extend about the interior of the form, interfitting couplingmembers connected to the opposed ends of the retainer and offsetlaterally therefrom, said members having wedge receiving openings and awedge insertible within said openings fdr expanding said retainer, oneof said members being ingsaid retainer, one of said members beingpivotally connected to the retainer, and means for securing the pivotedmember in operative position. 1

5. A retainer for forms of the character set forth, said retainercomprising a plurality of sections, interfitting members attached toadjacent ends of the adjoining sections and offset laterally therefrom,means pivotally connecting said members and furthermeans for forcingsaid members into properangular relation to each other and formaintaining them in such condi-. tion. r

6. A retainer for use with forms made up circmnferentially of aplurality of. plates, the adjacent edge portions of adjoining platesbeing turned inward for engagement with each other, said retainercomprising a plurality of sections corresponding in number to the numberof plates in the form, each section being arranged to repose between theopposed inturned edge portions of a plate, interfitting membersconnected to adjacent ends of adjoining sections, means connecting saidmembers, the members being shaped to bridge over the inturned edgeportions of the plates.

7. A retainer for use with forms made up circumferentially of aplurality of plates,"

the adjacent edge portions of adjoining plates being turned inward forengagement with each other, said retainer comprising a pluralityofsections corresponding in number to the number of plates in the form,each section being arranged-to repose between the opposed inturned edgeportions of a plate,

and meansconnecting adjacent ends ofadjoining sections, one of such endsbeing cut away to escape the inturned edge portions of the plates as theretainer is collapsed.

8. The. combination of form elements having adjacent edge portionsturned laterally for engagement with each other, a device comprisingmeans for clamping said edge portions together and having an abutmentopposed to said edge portions, and a member adapted to be wedged betweensaid abutment and the said edge portions for forcing such portions intoproper relation to each other. i

9. The combination of form elements having adjacent edge portions turnedlaterally for engagement with each other, a device comprising means forclamping said edge portions together, and a cam carried by said devicefor engagement with said edge portions for forcing them into properrelation to each other.

10. The combination of form elements having adjacent edge portionsturned laterally for engagement with each other, a device comprising apair of jaws arranged to have clamped between them said portions, amember extending transversely of the jaws, and a cam journaled upon saidmember for cooperation with the aforesaid edge portions for forcing saidportions into proper relation to each other. 7

11. The combination of fo 'm plates having adjacent edge portions turnedlaterally for engagement with each other, and a device comprising a pairof jaws arranged to have clamped between them. said edge portions, abolt for drawing said jaws toward each other, and a cam journaled uponthe bolt for engagement with the aforesaid edge portions whereby saidportions may be forced into proper relation to each other.

12. The combination of form plates having adjacent edge portions turnedlaterally and then back over their respective body portions thereby toproduce channels, and a device comprising opposed jaws having 30 partsfor the occupancy of said channels,

means for drawing said jaws toward each other, and further meansincorporated within said device for forcing the edge portions intoproper relation to each other.

13. The combination of form plates, having adjacent edge portions turnedlaterally and then back over their respective body portions thereby toproduce channels, and a device comprising opposed jaws having parts forthe occupancy of the said channels and means for drawing said jawstoward each other and including further means for forcing the edgeportions into proper relation to each other.

14. A form made up circumferentially of I HARRY O. DAVIDSON. OTTOHILLMAN.

Witnesses: v

WILLIAM W. LADD, HUGH B. MCGILL.

